• Disable logging in bindgen to reduce code size

    This disables bindgen's `logging` feature, which builds `env_logger`
    with default features, including regex support.  Disabling it allows
    Gecko to build `env_logger` without the `regex` crate, reducing code
    size.
    
    Part of https://bugzilla.mozilla.org/show_bug.cgi?id=1444097
    mbrubeck committed Mar 8, 2018